The State Government says it will investigate why Queensland Rail (QR) took five weeks to inform the Rail Safety Regulator (RSR) of potential hazards.
All services had to be suspended in the state's central west on Friday amid concerns more than 70 wooden bridges had not been properly inspected.
The RSR yesterday reopened the Emerald line to Longreach and Winton and launched a formal inquiry into claims staff had falsified safety inspections.
The lines from Emerald to Clermont and Springsure remain closed.
Premier Campbell Newman says QR may have broken the law by failing to inform the regulator sooner.
"We're going to get to the bottom of this," Mr Newman said.
"We are not going to put up with an organization that is top heavy, that is wasting their money but is not actually doing their fundamental job by ensuring that the network is safe." Mr Newman says failure to inform the Minister and the Director General of the Department of Transport and Main Roads is an incredibly serious thing and it may even be an illegal act.
Transport and Main Roads Minister Scott Emerson said one person had left QR and another had been suspended over the allegations.